For the production of cup-shaped receptacles comprising at least a receptacle wall and a receptacle bottom, a tool is used for pressing lower rim sections of receptacle wall and receptacle bottom together. The tool has an inner tool part and an outer tool part. The outer tool part essentially surrounds the receptacle at its lower end and is arranged outside of the receptacle. The inner tool part comprises a number of tool segments that are movable relative to the outer tool part between a retracted and a pressing position. In the retracted position it is possible to arrange corresponding rim sections between outer tool part and inner tool part. Then, the tool segments are moved in direction to the outer tool part and when the pressing position is arrived by the tool segments the lower rim sections of the receptacle wall and receptacle bottom are pressed together by opposed pressing surfaces of the outer tool part and the tool segments of the inner tool part. For a certain period of time, the corresponding lower rim sections are pressed together and then the tools segments are moved back to the retracted position and the receptacle is replaced by another receptacle for again pressing the corresponding lower rim sections together.
To securely fix the corresponding lower rim sections by such pressing, some kind of gluing or sealing substance is arranged, at least between those corresponding lower rim sections and, in particular, on surfaces of the rim sections that come into contact with each other by the pressing of the corresponding tool. Such a gluing or sealing substance may be a cold or hot glue or may also be a heated resin or resin layer applied to corresponding surfaces of at least one lower rim section. An example for such resin material is polyethylene, which is particularly used for receptacles made of paper or cardboard to provide some kind of sealing of the corresponding receptacle wall or receptacle bottom. Such resin material is heated at least up to its melting point.
When such gluing or sealing substance is able to flow during the pressing of the corresponding tool part, it can be squeezed by the tool part to be expelled to outer surfaces of the corresponding lower rim sections where the gluing or sealing substance may also adhere to the corresponding tool parts. Consequently, the corresponding gluing or sealing substance may contaminate the pressing surfaces of the tool parts. Such contamination may deteriorate the further operation of the tool parts and may also pollute the corresponding rim sections on the outer surfaces such that the outer appearance of the finished receptacle is negatively influenced. Furthermore, the gluing or sealing substance in contact with the pressing surfaces may at least partly harden during the pressing of the rim sections, such that when removing the inner tool part to the retracted position, delamination of the rim sections is caused. Such a delamination is generally detrimental in view of the sealing of the corresponding lower rim section that should be obtained by pressing the corresponding tool parts together with the lower rim sections therebetween.